Oil rate regulator for internal combustion engine tightness member

ABSTRACT

The tightness problem in internal combustion engines is usually solved by film between the apical portion of the segments and the chamber walls. The device disclosed herein is controlled by temperature sensitive means, so as to increase the rate of flow of the oil pump when the engine is cold, a condition which is particularly susceptible of causing damages due to cold wear.

United States Patent [191 Rombi et al.

OIL RATE REGULATOR FOR INTERNAL COMBUSTION ENGINE TIGHTNESS MEMBER Inventors: Pietro Rombi, Lainate; Nunzio DAlfonso, Milan, both of Italy Assignee: Alfa Romeo S.p.A., Milan, Italy Filed: Feb. 18, 1972 Appl. No.: 227,404

US. Cl. 184/6.l, 123/73 AD, 123/196 R Int. Cl. F01m l/l8 Field of Search 128/801, 196 R, 119 F, 128/73 F, 73 AD, 196 S; l84/6.1, 27 A, 6.26; 418/84, 87, 100

References Cited UNITED STATES PATENTS 12/1963 Werner et al. 123/73 AD ll/l958 Small l84/6.l

[ Apr. 16, 1974 3,140,700 7/1964 Nallinger 123/73 AD 3,343,526 9/1967 Peras l23/8.0l X 3,212,485 10/1965 Werner et al. 123/73 AD FOREIGN PATENTS OR APPLICATIONS 126,429 4/1919 Great Britain; l84/6.l 1,207,207 10/1970 Great Britain 184/6.l

Primary Examiner-Manuel A. Antonakas Attorney, Agent, or Firml-lolman & Stern 5 7] ABSTRACT The tightness problem in internal combustion engines is usually solved by film between the apical portion of the segments and the chamber walls. The device disclosed herein is controlled by temperature sensitive means, so as to increase the rate of flow of the oil pump when the engine is cold, a condition which is particularly susceptible of causing damages due to cold wear.

5 Claims, 3 Drawing Figures OIL RATE REGULATOR FOR INTERNAL COMBUSTION ENGINE TIGHTNESS -MEMBER BACKGROUND. OF THE INVENTION ofithecontacting surfaces and, according to the presentstatus of the engine-building art, several ways are known, whichare. moreor less efficient', to obtain it.

ltiisknownto feed the tightness members whichyslide against surfaces with, lubricating oil in, metered amounts as a function of; the rate of revolution and the engine load; Sucha meteringaction-is entrusted,tforexample, to oil-retainingpiston rings intthe reciprocating engines and? to lubricating oil metering devices on the rotary engines ofthe NSU-Wank'el type.

An oilifeedso metered hasproven to be inadequate to protectv the tightness members and the surfaces on whichthey slideas from: the corrosive compounds as formed'in a cold engine. lttshould be considered, more,- over, that when. the engine is cold, the lubricating oil encounters a greater difficulty in: being evenly spread on the surfaces due to its higherviscosity. It occurs, in

fact, that the most intensive wear is experienced with. cold. engines, i.e., from: starting and continuinglduring the time which is required by'the engine to attain. itsworking temperature.

Under these conditions, in order tooriginate a layer of lubricating oil between the surfaces, to a thickness which is sufficient to reduce wear or, at least, to'confine it within acceptable limits, it is suggested, according to the invention, the lubricating oil is supplied to the engine tightness members during the cold engine operation inan amount which exceeds the one supplied under the same operative conditions. as when the. engine is warm. This object is attained by the lubricating 'oil rate of flow regulating device according toithe present invention, which acts upon the. lubricating oil metering device as a function of the engine temperature,

in the sense of allowing an increase in the rate of flow of the lubricating oil during the time required by the engine to attain warm up.

The correction of the rate of flow of lubricant as obtained with-the device according to this invention permits todo away'with the defects enumerated above and concurrently permits to reduce the cold wear of the engine tightness members.

Said device, which carries out the regulation of the lubricating oil rate of flow asa function of the engine temperature, in the sense of increasing the rate of flow aforesaid, is operated either manually or automatically by a member which is sensitive to the engine temperature. Such a temperature information can be drawn from the temperature of the engine-cooling fluid, as well as from the temperature of the lubricating oil itself; orfrom any component part of the engine having a temperature that can-be used as a temperature referencing member. The device canbe applied to any internal combustion engine and more particularly, to rotary engines of the NSU-Wankel type. As is well known, engines ofthis kind are generally provided with a lubrication system in which the rate of flow of lubricating oil to, theapical tightness segments is regulated'by a metering pump which send the lubricant directly into the stator or the carburetor float chamber in an amount which is increased as the rate of revolution of the engine is increasedand often also as the engine load is increased (position of the throttle).

SUMMARY OF THE INVENTION According to the invention, a device for regulating the rated flow of thelubrication oil to the sliding tightness members of the combustion chamber of an internal combustion engine comprises an apparatus for feeding oil to said members at a rate of flow which is a function at least of one of the parameters formed by the. rateof revolution of the engine and the engine load, andisfurther characterized by comprising means sensitive to the engine temperature and acting upon said apparatus in the sense of causing the rate of flow thereof tobe increased as determined by said parameters when said temperatures lie below a preselectedvalue.

BRIEF DESCRIPTIONOF THE DRAWINGS In order that the objects andthe features of the device according-to-theinvention may become clearer, an exemplary embodiment will be described hereinafter and-illustrated in the accompanying drawings, wherein:

FIG. 1 is a diagrammatical view of a regulating device as applied to-an internalcombustion engine.

FIGS. 2' and, 3; are close up viewsof details of FIG. 1 in the: different position as taken in operation.

DETAILED DESCRIPTION or THE PREFERRED EMBODIMENT 7 there is the pivot thereof, 17 being the transfer lever pivoted. at. 18, which has one end' 33 of the lever arm resting against the accelerator pedal and is connected at the end of the. other arm by the hinge 34 to the rod 20.v In this position, there is applied the return spring 31, the rod 20 being connected by the hinge 32 to the lever 30 which is made integral with, the butterfly throttle, 14 inserted in the duct 11, the throttle being rotatable about its pivot 19.

At 50 there is indicated the oil pump which draws oil from the pump 51 and sends it through the piping 52 to the component members of the engine which require it, as well as to the metering pump 53 via the piping 54.

The arbor 36 of the metering pump receives its drive from the mainshaft 57 through a belt drive as diagrammatically shown at 29, in the drawing; where there have been shown in dotted lines the sheave 37 is keyed to the pump arbor, the sheave 38 being keyed to the arbor 57. Thus the metering pump delivers a rate of flow of oil which is proportional to the angular speed of the sheave 37 and thus is a function of the engine rate of revolution. The metering pump sends the lubricant, through the piping 21, to the float chamber 22 of the carburetor, wherein the level is kept constant by the float 46. In the float chamber, the oil is admixed to the gasoline and, through the duct 40, in which the usual calibrated hole 23 of the carburetor is inserted, is sent to the intake duct 11 at the Venturi 13, where admixture with air takes place, so that the oil enters the engine together with the fuel mixture and provides to lubricate the tightness members (not shown) of the rotor of the engine 10. The rate of flow as delivered by the metering pump is also regulated as a function of the engine load by a conventional delivery regulation device (not shown), controlled by the lever 56, which can take a number of positions inasmuch as it can be rotated about the pin 41 which actuates the regulator internal to the pump 53. The other end of the lever is inserted in the slot 58 formed in the pitman 59, the latter being connected to the lever 30 of the throttle by means of the hinge 32.

In the drawing 24 indicates a thermostatic capsule which is sensitive to the temperature of the enginecooling fluid or the lubrication oil or of any component part of the engine which can be taken as a reference of the engine temperature. 26 indicates the rod which is connected by the hinge 39 to the rod 43 of the thermostatic capsule 24, the rod 26 having the slot 60 in which the end of an arm of the transfer lever 27 is inserted, the lever being fulcrumed at 61, whereas the other arm of the lever is connected by the hinge 62 to one end of the rod 28, the latter being connected by the hinge 42, at the other end, to the body of the lever 56. On the lever 56 is active the return spring 25 which tends to maintain the lever in a position which corresponds to the minimum rate of flow as delivered by the metering pump, by urging the lever to rotate clockwise.

FIG. 1 shows the positions as taken by the several component parts of the device under the closed throttle and cold engine conditions; the thermostatic capsule 24, by means of the rod 26, the pitman 27 and the rod 28 maintains the lever 56 of the metering pump 53 in the maximum rate of flow area. The slot 58 of the lever 59 allows this displacement without influencing the position of the throttle.

In FIG. 2, the device is shown in the position it takes under the conditions of closed throttle and warm engine. The thermostatic capsule 24 causes the rod 26 to be lifted, so that the lever 56, which is no longer subjected to the pull of the lever 28, can be positioned, under the bias of the return spring 25, in the position of minimum rate of flow of lubrication oil.

In FIG. 3, the device is shown under the conditions of open throttle and warm engine. The lever 56 is in a position which is intermediate between the maximum and minimum rate of flow of oil and the rod 26, just because it has the slot 60, does not influence its displacement which takes place only as a function of the posi tion of the throttle. The advantage achieved by the device according to the invention over the conventional devices is now clearly apparent, inasmuch as the known devices effect a regulation of the rate of flow of lubricating oil as a function of the rotational speed of the engine and the engine load in such a manner as to intro duce into the engine an amount of oil according to an approximately constant ratio with respect to the amount of gasoline or at an increased rate as a function of the engine load. These known devices afford a sufficient reduction of the wear of the sliding component part when the engine has attained its working temperature, but the amount of oil which is delivered is positively insufiicient to limit wear during cold engine operation. As a matter of fact, under these conditions, a much greater amount of lubricating oil is required, which is then reduced to the normal values by the device in question when the engine is warm, thus preventing an unnecessary waste of lubricant and thus an exceedingly high consumption of oil. In the known devices, during the engine idling, the lever 56 of FIG. 1, connected through the leverages described hereinbefore to the accelerator pedal, would remain in the minimum rate of flow position also in the cold engine state, whereas the device according to the present invention displaces it towards the maximum rate of flow position.

This device also permits obtaining, under cold engine conditions, a delivery of lubricating oil which is even higher than the maximum one which can be obtained under warm engine conditions, since the latter is also restricted by the requirement of maintaining the oil consumption within acceptable limits. The magnitude of this excess rate of flow can be established on the basis of the engine requirements by varying the positions and/or the lenghts of the slots 58 and 60. The automatic displacement of the lever of the metering pump can be embodied, of course, in addition to a system similar to the one described herein (or, as has been said, manually), also with other electromechanical, pneumatic or hydraulic systems. What has been described is given by way of example only. A similar device can be applied to injection engines in which the metered lubricant is sent directly to the stator or to the intake ducts.

What we claim is:

1. A device regulating the rate of flow of lubricating oil to the sliding tightness members of the combustion chamber of an internal combustion engine, said device comprising in combination with said engine:

supply means for supplying oil to said members at a rate of flow which is a function of at least one of the parameters comprising the rate of rotation of the engine and the engine load; temperature sensing means for sensing the engine temperature; and

override means coupled to said supply means, said override means being responsive to said engine temperature determined by said temperature sensing means for increasing the rate of flow of said supply means over that determined by said parameters when said temperature is below a preselected value.

2. A device as claimed in claim 1, wherein said temperature sensitive means are members which are automatically controlled by a thermostatic capsule which is sensitive to said working temperature of the engine.

3. A device as claimed in claim 1, wherein said supplying means is a pump and said temperature-sensitive means act thereon in the sense of increasing the rate of flow thereof.

4. A device as claimed in claim 3, wherein said pump is equipped with a rate of flow regulating device connected to said temperature-sensitive means through a leverage defining said override means which acts upon 6 a control in said device in the sense of increasing the livered by said pump. rate of flow delivered by said pump when said tempera 5. A device as claimed in claim 1, wherein said supture is below a pre-selected value, said leverage leaving said control free to be actuated as a function of said parameters in the sense of varying the rate of flow as de- 5 plying means introduces oil into the engine intake duct.

NITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3804201 Dated April 16. 1974 '[nventor(s) Pietro Rombi and Nunzio D'Alfonso It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Foreign Application Priority Data February 23, 1971 Italian No. 20932 Signed and sealed this 17th day of September 1974,

(SEAL) Attest:

McCOY M. GIBSON 'JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents USCOMM-DC 60376-P69 $7 UIS. GOVERNMENT PRINTING OFFICE 1 I569 0-366-334,

1 FORM PO-1050(10-69) 

1. A device regulating the rate of flow of lubricating oil to the sliding tightness members of the combustion chamber of an internal combustion engine, said device comprising in combination with said engine: supply means for supplying oil to said members at a rate of flow which is a function of at least one of the parameters comprising the rate of rotation of the engine and the engine load; temperature sensing means for sensing the engine temperature; and override means coupled to said supply means, said override means being responsive to said engine temperature determined by said temperature sensing means for increasing the rate of flow of said supply means over that determined by said parameters when said temperature is below a preselected value.
 2. A device as claimed in claim 1, wherein said temperature -sensitive means are members which are automatically controlled by a thermostatic capsule which is sensitive to said working temperature of the engine.
 3. A device as claimed in claim 1, wherein said supplying means is a pump and said temperature-sensitive means act thereon in the sense of increasing the rate of flow thereof.
 4. A device as claimed in claim 3, wherein said pump is equipped with a rate of flow regulating device connected to said temperature-sensitive means through a leverage defining said override means which acts upon a control in said device in the sense of increasing the rate of flow delivered by said pump when said temperature is below a pre-selected value, said leverage leaving said control free to be actuated as a function of said parameters in the sense of varying the rate of flow as delivered by said pump.
 5. A device as claimed in claim 1, wherein said supplying means introduces oil into the engine intake duct. 